Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

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Now showing 1 - 8 of 8
  • Article
    Citation - WoS: 30
    Citation - Scopus: 33
    Processing and Compression Testing of Ti6al4v Foams for Biomedical Applications
    (Springer Verlag, 2009) Dizlek, Mustafa Eren; Güden, Mustafa; Türkan, Uğur; Taşdemirci, Alper
    Open cell Ti6Al4V foams (60% porosity) were prepared at sintering temperatures between 1,200 and 1,350 °C using ammonium bicarbonate particles (315–500 μm) as space holder. The resulting cellular structure of the foams showed bimodal pore size distribution, comprising macropores (300–500 μm) and micropores (1–30 μm). Compression tests have shown that increasing sintering temperature increased the elastic modulus, yield and compressive strength, and failure strain of foams. The improvements in the mechanical properties of foams prepared using smaller size Ti64 powder with bimodal particle distribution were attributed to the increased number of sintering necks and contact areas between the particles. Finally, the strength of foams sintered at 1,350 °C was found to satisfy the strength requirement for cancellous bone replacement.
  • Article
    Citation - WoS: 4
    Citation - Scopus: 5
    Improving the Energy Absorption of Closed Cell Aluminum Foams
    (Chapman & Hall, 2002) Greene, S. A.; Hall, Ian W.; Güden, Mustafa
    Closed cell aluminum foams have received much recent attention as energy absorbing materials on account of their ability to undergo extensive deformation at a relatively low stress called the plateau stress. Several studies describe the improvements in energy absorption to be obtained, relative to their empty counterparts, when foam filled tubes are crushed either quasi-statically or dynamically [1–4]. Al foams are also of possible interest for ballistic applications because they present a very large acoustic impedance mismatch with common armor materials, offering the possibility of being able to modify theway in which elasticwaves travel through multi-component armor.
  • Article
    Citation - WoS: 5
    Citation - Scopus: 5
    Foaming Behavior of Ti6al4v Particle-Added Aluminum Powder Compacts
    (Springer Verlag, 2009) Karsu, Nurettin Deniz; Yüksel, Sinan; Güden, Mustafa
    The foaming behavior of 5 wt.% Ti6Al4V (Ti64) particle (30–200 μm)-added Al powder compacts was investigated in order to assess the particle-addition effects on the foaming behavior. Al compacts without particle addition were also prepared with the same method and foamed. The expansions of Ti64 particle-added compacts were measured to be relatively low at small particle sizes and increased with increasing particle size. At highest particle size range (160–200 μm), particle-added compacts showed expansion behavior similar to that of Al compacts without particle addition, but with lower expansion values. Expansions studies on 30–45 μm size Ti64-added compacts with varying weight percentages showed that the expansion behavior of the compacts became very similar to that of Al compact when the particle content was lower than 2 wt.%. However, Ti64 addition reduced the extent of drainage. Ti64 particles and TiAl3 particles formed during foaming increased the apparent viscosity of the liquid foam and hence reduced the flow of liquid metal from cell walls to plateau borders. The reduced foamability in the compacts with the smaller size Ti64 addition was attributed to the relatively high viscosities, due to the higher cumulative surface area of the particles and higher rate of TiAl3 formation between liquid Al and Ti64 particles.
  • Article
    Citation - WoS: 19
    Citation - Scopus: 19
    Experimental Investigation of Interaction Effects in Foam-Filled Thin-Walled Aluminum Tubes
    (Springer Verlag, 2006) Güden, Mustafa; Toksoy, Ahmet Kaan; Kavi, Halit
    The interaction coefficients of polystyrene foam filling of thin-walled aluminum cylindrical tubes were investigated experimentally through compression testing of partially foam-filled tubes with and without adhesive. The experimental load-displacement curves and observation of the crushed sections of filled tubes have shown that partial foam filling reduced the fold length and hence increased the average crushing loads of tubes, proving the interaction effect between tube wall and filler. The interaction coefficients for the partial foam filling were further calculated to be in the level and/or higher than that of the foam plateau load of transverse direction.
  • Article
    Citation - WoS: 29
    Citation - Scopus: 29
    Effect of Adhesive on the Strengthening of Aluminum Foam-Filled Circular Tubes
    (Springer Verlag, 2004) Toksoy, Ahmet Kaan; Tanoğlu, Metin; Güden, Mustafa; Hall, Ian W.
    Studies of the crushing behavior of closed-cell, aluminum foam-filled aluminum and steel tubes have shown an interaction effect between tubewall and foam filler [1, 2, 3]. The crushing loads of foam-filled tubes are, therefore, found to be higher than the sum of the crushing loads of foam (alone) and tube (alone) mainly due to this effect. Santosa et al. [1], based on FEM results, proposed the following equation for the average crushing load of foam-filled square tubes of length b,
  • Article
    Citation - WoS: 194
    Citation - Scopus: 227
    Dynamics of Metal Foam Deformation During Taylor Cylinder–hopkinson Bar Impact Experiment
    (Elsevier Ltd., 2003) Lopatnikov, Sergey L.; Gama, Bazle A.; Haque, Jahirul; Krauthauser, Carl; Gillespie, John W.; Güden, Mustafa; Hall, Ian W.
    Analytical solutions for dynamic deformation of foam materials during the Taylor cylinder–Hopkinson bar impact experiment were obtained. It was shown that shock wave of foam collapse appears during the fast impact. The results of this experiment can be used in estimating the average material properties of the foam under dynamic loading conditions. Results show that the un-deformed and change in length of foam specimens are in good agreement between theory and experiment, as well as numerical analysis.
  • Article
    Citation - WoS: 124
    Citation - Scopus: 136
    Crushing of Aluminum Closed Cell Foams: Density and Strain Rate Effects
    (Elsevier Ltd., 2000) Hall, Ian W.; Güden, Mustafa; Yu, C.-J
    The quasi-static and high strain rate compression behavior of an Al closed cell foam was examined in detail. The compression flow stress of the foam was a function of the relative density but exhibits little or no strain rate density. In addition to the flow stress, the energy absorption was also related to the foam density by a similar power law dependency. Metallographic observations of compressively deformed foam confirmed the general processes of progressive cell wall collapse.
  • Article
    Citation - WoS: 10
    Citation - Scopus: 10
    Open Cell Lead Foams: Processing, Microstructure, and Mechanical Properties
    (Springer Verlag, 2012) Savacı, Umut; Yılmaz, Sinan; Güden, Mustafa
    Open cell lead foams with the porosities between 48 and 74 % were prepared by means of powder metallurgical and casting routes, using ammonium bicarbonate particles, silica beads, and sodium chloride salt particles as space holder. The resulting foam samples structure closely resembled open cell foam structure: each cell had few interconnections with neighboring cells. Small-sized lead (II) fluoride precipitates were microscopically observed in the interior of cells in the foam samples prepared using silica beads as space holder, resulting from the reaction between silica and hydrofluoric acid in the space holder dissolution step. The compression stress–strain curve of foam samples prepared by powder metallurgical route showed brittle deformation behavior following the initial elastic deformation region, while the foam samples prepared by casting route showed characteristic foam deformation behavior: cell edge crushing on the bent cell walls, and cell wall tearing. The collapse stresses, densification strains, and elastic moduli of the prepared foams were further fitted with scaling relations.